Isolation-mounted vibratory reed device



17 H. 5. LEHMANN 3,337,826

ISOLATION-MOUNTED VIBRATORY REED DEVICE Filed March 7, 1966 INVENTOR. Herber G .Lehmunn til I I ABSTRACT OF THE DISCLOSURE An isolation-mounted vibratory electrical reed device comprising a tubular casing closed at both ends. At one of the closed ends contact pins project and are insulatedly supported. Within the casing in an elongate frame or base carrying an electrical reed and a driving coil for the same, resiliently connected to the inside ends of the contact pins by separate, small diameter helical suspension springs. The other end of the frame is resiliently connected to the other end of the casing by a composite or compound suspension spring having a main helical portion extending between said other ends and recessed in the frame end, said spring having at one end of the helical portion a large-diameter spiral portion which snugly fits within the said other casing end.

This invention relates to vibratory reed devices, and more particularly to devices of this type wherein the reed movement is shock-mounted or vibrationally isolated, to minimize the effect of external forces, shock and the like.

Objects of the invention are to provide an improved shock-mounted vibratory reed device which has especially uniform shock-resistant characteristics while at the same time utilizing spring components all of which are capable of economical, mass production by means of well-known manufacturing processes; to provide an improved reed device as above characterized, wherein severe shocks are effectively handled by a novel damping action of the shock-absorbing and isolating means; to provide a reed device in accordance with the foregoing, wherein resonant foreign vibrations are minimized; and to provide an improved shock-mounted reed device having the above features and advantages while still being simple in structure, easily and quickly assembled, and low in manufacturing cost.

In the drawings:

FIG. 1 is a longitudinal sectional view through a reed device which is shock-mounted in a shielding casing, as provided by the invention.

FIG. 2 is a longitudinal sectional view similar to that of FIG. 1, but taken on a plane which is at right angles to the plane of the section of FIG. 1.

FIG. 3 is a bottom plan view of the shock-mounted reed device.

FIG. 4 is a side elevational view, greatly enlarged, of a compound-action suspension spring as provided by the invention and utilized in the spring device of FIGS. 1 and 2.

FIG. 5 is an end elevational view, also greatly enlarged, of the compound suspension spring of FIG. 4.

Referring first to FIGS. 1 and 2, the shock-mounted reed device comprises an elongate tubular casing 10 which is preferably of rectangular or square cross sectional shape, said casing having an integral transverse top wall 12 and at its other end being provided with a close fitting insulating base 16 of square outline, carrying a circular insert disk 14 in which there are mounted contact pins 18 arranged in a well known octal configuration. The disk 14 and pins 18 constitute a conventional 7-pin miniature n States Patent {rise commonly used for relays, vacuum tubes and the Disposed within the casing 10 is a floating elongate frame 20 having a U-shaped section or channel configuration, with side walls 22, 24 and a connector or middle portion 26.

At one end the frame 20 mounts a terminal block 28 to which there are secured mounting and connector springs 30, said springs depending from the terminal block 28 and being connected to appropriate contact pins 18. As shown herein, four such springs 30 are utilized, connected respectively to four of the contact pins 18 whereby the said one end of the frame 20 is shock-mounted in the casing 10 in spaced relation thereto.

At its other end the frame 20 has secured in it a reed mounting block 32, in which there is fastened and from which there depends a vibratory reed 34. The reed 34 extends through the central opening or air core of an exciting coil 36, and also extends through the opening or gap of a permanent magnet 38, said coil and magnet being rigidly secured in the frame 20 adjacent the one end thereof, and spaced axially from the terminal block 28.

The coil 36 is connected by leads 40, 42 to two of the springs 30, and if desired an additional connection may be made to the third one of the springs 30 from the frame 20 whereby the reed 34 will be electrically connected to a contact pin 18.

With the above arrangement, a suitable alternating exciting current in the coil 38 will effect an oscillation of the reed 34 by virtue of the reed exhibiting magnetism induced from the permanent magnet 38. Upon the exciting current having the frequency which coincides with the resonant frequency of the reed 34 a maximum oscillation or vibration of the said reed will occur.

By the present invention, the upper end of the frame 20 and casing 10 are mechanically connected by a novel shock-absorbent means, to complete the shock mounting of the frame and also to effectively isolate the latter and minimize the effect of external vibration, shock and the like on the action of the reed 34.

As seenin FIGS. 1 and 2, the said upper end of the frame 20 has an insulator block 46 in which there is a central recess 48 which opens upward. A novel shockabsorbing suspension spring 50 is provided, said spring being of compound construction having a helical body portion 52 and a spiral anchorage portion 54. The helical body portion 52 is snugly received in the recess 48 of the insulator block 46, and the spiral anchorage portion 54 is snugly received in the closed top portion of the casing 10, as shown. The compound spring 50 is constituted entirely of a single piece of resilient wire such as music wire or the like. Preferably, one end 56 of the helical body portion 52 is tight wound, as clearly seen in FIG. 4. Also, preferably the spiral portion 54 of the spring has at least two complete convolutions as the spiral increases in diameter to the outer periphery. Further, the outer peripheral portion of the spiral 54 preferably has at least one and one-half convolutions, as indicated in FIG. 5. The helical body portion52 has its convolutions spaced, and I have found that a configuration as illustrated in FIGS. 4 and 5 provides an effective and advantageous suspension for small vibratory reed devices if a wire size of approximately .023 diameter is utilized, with the body portion 52 being approximately 78 of an inch in diameter, and the outer'periphery of the spiral anchorage portion 52 being approximately of an inch in diameter. With these dimensions, the casing 20 will then be made to have an inside size of of an inch on a side, and the frame 20 may have a transverse dimension of approximately of an inch on a side. However, it will be understood that the invention is not limited to the specific example set forth above, since other sizes and arrangements are possible Within the spirit of the invention.

Preferably when the suspension spring 50 is assembled to the frame 20 and within the casing 10, the helical body portion 52 is under axial compression whereby the upper end of said body portion frictionally engages the transverse top wall 12 of the casing. This frictional engagement has an advantageous damping effect. For example, if the top portion of the casing suffers a fairly severe blow, the convolutions of the spiral portion 54 of the spring will yield slightly. However, the accompanying movement of the upper end of the helical body 52 will be restrained somewhat by the frictional engagement with the top wall 12 of the casing, whereby the tendency for such top end of the helix to oscillate freely will be restricted or damped.

Thus, the compound spring 50 has an advantageous action when the reed device is subjected to relatively strong external vibration or forces. The ability of the upper end of the helical body 52 to shift provides for a restrained greater flexibility of the suspension spring. For small external vibrating forces the helical body portion 56 will absorb the same due to the frictional engagement of the upper end of the said body portion with the top wall 12 of the casing in conjunction with the connection represented by the spiral convolutions of the portions 52. The frictional engagement between the upper end of the helical body portion 52 and the top wall 12 of the casing 10 prevents oscillation at or near resonant frequencies, of the upper end of the suspension spring.

By the isolation due to the spring suspension, the vibrations of the reed mounting block 32 are not fully transmitted to the casing 10, minimizing the reaction of the latter during oscillation of the reed.

I have found that a compound suspension spring such as that indicated at 50 in the figures thus has an advantageous action in confining internal vibrations, and also in coping with both strong and weak external vibrations or forces to which the casing 10 may be subjected. The close fit of the spring 50 in the recess 48, and the confinement of the outer peripheral portion 58 of the spring in the top portion of the casing 10 result in an effective mounting being established between the upper ends of the casing 10 and frame 20, which'mounting will not fail or malfunction even during rough usage of the reed device.

In conjunction with the mounting-conductor springs 30, the suspension spring 50 effectively shock-mounts the frame 20 and minimizes the effect of internal and external vibrations and forces, the latter not adversely affecting the natural resonant response of the reed 34.

While the drawings show a reed device known as an oscillator control, it will be understood that the invention has utility for reed devices generally, including devices arranged to function as frequency sensitive relays,

wherein the reed is engageable with an electrical contact.

Variations and modifications may be made Within the scope of the claims, and portions of the improvement may be used without others.

I claim:

1. A vibratory reed device comprising, in combination:

(a) an elongated tubular casing,

(b) a floating elongate frame in and spaced from said casing,

(c) a magnetic reed and exciting coil carried by the frame,

(d) contact pins insulatedly carried by and projecting from one end of the casing,

(e) helical coil springs connected to the contact pins and one end of the frame, floatingly mounting the latter in the casing,

(f) slaid springs being electrically connected to the cor (g) a single suspension spring connected between the other ends of the frame and easing,

(h) said suspension spring comprising a helical body portion and a spiral anchorage portion connected to one end of the body portion and extending outward therefrom,

(i) the other end of said helical spring portion being connected to said frame end,

(j) the outer convolution of said spiral spring portion being nested within said other end of the casing, (k) said helical coil springs and said suspension spring being maintained under continual compression by said casing and frame, and

(l) the spiral portion of said suspension spring yieldably supporting said one end of the helical body portion thereof, and becoming operative for shocks of a higher order of magnitude to which the casing may be subjected.

2. A vibratory reed device as in claim 1, wherein:

(a) said one end of the helical body portion of the suspension spring frictionally engages an end wall of the casing under spring pressure and is damped thereby, effecting a restraint against free oscillation.

3. A vibratory reed device as in claim 1, wherein:

(a) said spiral spring portion comprising at least two complete turns.

4. A vibratory reed device as in claim 1, wherein:

(a) said spiral spring portion having essentially two peripheral coils of substantially the same diameter.

5. A vibratory reed device as in claim 1, wherein:

(a) said other end of the frame having a cylindrical socket in which said other end of the helical spring portion is received and confined.

References Cited UNITED STATES PATENTS 2,688,059 8/1954 HolZinger et a1 33594 3,221,120 11/1965 Mooney et al 335- BERNARD A. GILHEANY, Primary Examiner.

H. BROOME, Assistant Examiner. 

1. A VIBRATORY REED DEVICE COMPRISING, IN COMBINATION: (A) AN ELONGATED TUBULAR CASING, (B) A FLOATING ELONGATE FRAME IN AND SPACED FROM SAID CASING, (C) A MAGNETIC REED AND EXCITING COIL CARRIED BY THE FRAME, (D) CONTACT PINS INSULATEDLY CARRIED BY AND PROJECTING FROM ONE END OF THE CASING, (E) HELICAL COIL SPRINGS CONNECTED TO THE CONTACT PINS AND ONE END OF THE FRAME, FLOATINGLY MOUNTING THE LATTER IN THE CASING, (F) SAID SPRINGS BEING ELECTRICALLY CONNECTED TO THE COIL, (G) A SINGLE SUSPENSION SPRING CONNECTED BETWEEN THE OTHER ENDS OF THE FRAME AND CASING, (H) SAID SUSPENSION SPRING COMPRISING A HELICAL BODY PORTION AND A SPIRAL ANCHORAGE PORTION CONNECTED TO ONE END OF THE BODY PORTION AND EXTENDING OUTWARD THEREFROM, 